This invention relates to a kit and method for determining redox status in urine. The invention relates in particular to such a kit and such a method in which the determination of redox status can be carried out extremely easily on the basis of the color reaction with a reagent selected from the group of indole derivatives by visual color comparison, i.e., with the naked eye.
The human body is exposed to a large number of loads causing free radicals to be produced in the cells of the body, particularly under the present environmental conditions. These loads include, for example, cigarette smoke, car exhaust gases, UV radiation, and various other noxious substances. The free radicals produced, which also include oxygen free radicals, form pathogenic products of degradation, which are able to cause sustained damage to various components within the cells of the body cell in a wide variety of subsequent oxidative reactions. The consequences of this damage include, for example, premature aging, but also serious diseases such as diabetes or cancer.
In order to neutralize, i.e., bind free radicals, which also occur to a limited degree under ideal environmental conditions, the human body has developed a number of systems with an anti-oxidative system. However, these systems are frequently overloaded, among other things, because of lifestyles and the particular environmental situation of the human being, so that free radicals in the body cannot be rendered sufficiently harmless. In such cases, it is necessary to stimulate or support the body""s own anti-oxidative systems by eating special food supplements (micro-nutrient preparations from vitamins and trace elements). In such a treatment, the quantity of drugs administered or supplements taken should be adapted to the actual loading of the body with free radicals.
Ideally, the determination of the load exerted by free radicals should be carried out by the patient himself/herself without major expenditure, quickly, and at low cost. Such a determination may therefore be carried out on the basis of urine samples in particular.
The fundamental objective of this invention is therefore to determine redox status in urine by simple means, i.e., by the naked eye. xe2x80x9cDetermination of redox statusxe2x80x9d is defined in this connection as obtaining a quantitative, semi-quantitative, or qualitative statement on the concentration and presence of free radicals in the human body, i.e., on the oxidative loading of the organism. The malonic dialdehyde in the urine serves as an indicator substance for this statement, but other relevant substances can also be recorded, as appropriate.
This objective is achieved according to the invention by a kit for determining redox status in urine, comprising:
(a) at least one reagent selected from the group of compounds with the general formula (I) 
wherein R1 is H or C1-C10-alkyl;
and wherein R2 is independently selected from the group consisting of H; C1-C10-alkyl; NH2; NHR; NR2; NHCOR; OH; OR; OCOR; SH; SR; F; Cl; Br; CF3; or CCl3, and wherein each R is selected from the group consisting of C1-C6-alkyl;
and wherein R3 and R4 are independently selected from the group consisting of H; C1-C10-alkyl; NH2; NHR; NR2; NHCOR; OH; OR; OCOR; SH; SR; F; Cl; Br; CF3; CCl3; C6-C14-aryl; C6-C14-aryl, wherein the aryl group is substituted by one or more substituents selected from the group consisting of C1-C6-alkyl, NH2, NHR, NR2, NHCOR, OH, OR, OCOR, SH, SR, F, Cl, Br, CF3 and CCl3, and wherein each R is selected from the group consisting of C1-C6-alkyl;
(b) at least one acid; and
(c) a color scale for the visual color comparison, where a certain redox status of the urine to be analyzed is assigned to individual colors on the scale.
According to a further embodiment of the invention, a method is also provided for determining redox status in urine, comprising the following stages:
(a) Mixing of a urine sample to be analyzed with
(i) at least one reagent selected from the group of compounds with the general formula (I) 
wherein R1 is H or C1-C10-alkyl;
and wherein R2 is independently selected from the group consisting of H; C1-C10-alkyl; NH2; NHR; NR2; NHCOR; OH; OR; OCOR; SH; SR; F; Cl; Br; CF3; or CCl3, and wherein each R is selected from the group consisting of C1-C6-alkyl;
and wherein R3 and R4 are independently selected from the group consisting of H; C1-C10-alkyl; NH2; NHR; NR2; NHCOR; OH; OR; OCOR; SH; SR; F; Cl; Br; CF3; CCl3; C6-C14-aryl; C6-C14-aryl, wherein the aryl group is substituted by one or more substituents selected from the group consisting of C1-C6-alkyl, NH2, NHR, NR2, NHCOR, OH, OR, OCOR, SH, SR, F, Cl, Br, CF3 and CCl3, and wherein each R is selected from the group consisting of C1-C6-alkyl;
(ii) at least one acid; and
(b) after a stable coloration of the sample has been achieved, visual comparison of the coloration of the sample with a color scale, a specific redox status of the urine to be examined being assigned to the individual colors of the scale.
The kit and the method according to the invention are based on a color reaction, which shows the reagent having the formula (I) under acid conditions when mixed with the urine sample to be analyzed. This color reaction results in the formation of a colored dye characteristic of the initial reagent, the intensity of the coloration depending on the oxidative loading of the organism. In this case, the heavier this load, i.e., the higher the concentration of free radicals in the body, the more intensive the coloration. In general, the color of the sample that can be perceived with the naked eye is also influenced by the color of the urine analyzed.
This color reaction is initiated in particular by the presence of malonic dialdehyde in the urine analyzed. Malonic dialdehyde is a product of degradation of certain hydroperoxides, which are formed by the oxidation of unsaturated fatty acids of the cell membrane in the organism. Since oxidative stress results in intensified lipid oxidation of the cell, it also causes an increase in the concentration of malonic dialdehyde in the urine. This increase can be determined by means of the kit and method according to the invention, so that countermeasures can then be taken, depending in particular on the intensity of the load, e.g., measures such as strengthening the anti-oxidative defense by taking suitable vitamins and trace elements and/or altering one""s lifestyles (smoking, diet, living/working environment).
The redox status is determined by means of the kits according to the invention, and by the method according to the invention, by mixing together the reagent, the acid, and the urine sample at room temperature, whereupon the coloration stabilizes, depending in particular on the intensity of the oxidative load. The color reaction is generally completed within 15 to 60 minutes, and in preferred embodiments within 15 to 30 minutes. Afterwards, i.e., as soon as the intensity of the coloration stops increasing, this intensity is determined visually, i.e., by the naked eye, by comparison with a color scale. In this case, the color scale consists of a number of discrete color elements, which are arranged according to their intensity and whose colors correspond to the coloration of the sample solution after termination of the color reaction, according to redox status.